Systematic Reviews

You learned that Systematic Reviews are "Type III" Resources. They provide the current status of evidence, based on analysis of every available large Trial

Let us understand "The Cochrane Reviews"

 If you wish to understand what a Cochrane Review is, in very simple terms (or explain it to a student or a layperson) here is a lovely blog post from the South Asian Cochrane Centre, Vellore, India

Cochrane Reviews are available from the Cochrane Library -

Let us search for and find a Cochrane Review on a topic - Is Azithromycin a drug of choice for Typhoid
  • Go to the Cochrane Library and in the Search box type Azithromycin AND Typhoid
  • In the result page you will find a Cochrane Review:

    Azithromycin for treating uncomplicated typhoid and paratyphoid fever (enteric fever)

  • Click this title
  • You will first see a "Structured Abstract" and below that - a "Plain language summary". The abstract tells you how they followed a strong methodology (Seven trials with over 700 patients) to work on the review. And summary tells you in simple language that while Azithromycin is better than many drugs, we need to watch out for development of resistance

Now click the "Figures" tab. Click the second Figure - comparing "
Azithromycin (AZM) vs fluoroquinolones (FQ):" to check the outcome of  "Clinical failure"
You see what is called a Forest Plot - where the studies fall on the side that shows "Favours AZM". 

Check out some more figures too

In this way, even by just seeing the plain language summary and the Forest Plots, we get to know the results of a "Meta-Analysis"  of several trials from a Cochrane Review


If you wish to learn more about appraising Systematic Reviews:

CASP-UK has put up Appraisal Tools for Research. 
Here is a link to these tools. Check out the one on Systematic Reviews